Stressors are “aversive agents,” including situations that are taxing or threatening (Evans & Cohen, 1987, p. 575) and lead to stress and the reactions to it. Selye, from whom the current ideas about “stress” originated, defined the concept of human stress as “the nonspecific response of the body to demands” (Selye, 1976c, p. 1) and associated it with psychological responses and multiple organ system physiological responses that may affect mental and physical health (Selye, 1946; Selye, 1976c). The totality of these adaptive reactions and the changes they produce in the human body (“the stress syndrome . . . general adaptation syndrome (G.A.S.),” Selye, 1976c, p. 1) are the subject of much attention because of the significance of the syndrome to health and health costs. The neuroendocrine responses to stress affect the human system as a whole and can impact every major organ, as well as more generalized inflammatory or infectious conditions that target multiple areas of the body (Benson & Klipper, 1975; Selye, 1976c). To name a few of the more significant issues, the stress syndrome can exacerbate heart disease, diabetes, eating and weight issues, mental health, and possibly even the growth of cancer, thereby making the treatment of these afflictions more complicated and more costly to individuals, their caregivers, and their society. To reduce this extremely pervasive stress reaction is to effect positive change in both individuals and health systems everywhere.
One means by which to address the stress reaction is with natural landscape images. Visual stimuli, as a primary sensory input processed in the brain, may provoke either positive or negative physiological responses and/or self-reported psychological states. In some cases, for example, the viewing of a complicated and unrecognizable picture, such as a piece of abstract art, challenges the mind to essentially decode the picture in creative terms in order to interpret the image, provoking an anxious state. On the other hand, certain types of images, such as images of natural landscape scenes, may elicit a physiological and/or psychological relaxation response, particularly when such images have specific characteristics as further described herein.
This has been discussed by theorists and documented in laboratory and clinical studies. Viewing photographic natural landscape scenes has been shown to reduce physiological and psychological indicators of stress in several laboratory studies with healthy young adults (Chang & Perng, 1998; Parsons, Tassinary, Ulrich, Hebl, & Grossman-Alexander, 1998; Tse, Ng, Chung, & Wong, 2002; Ulrich, 1979; Ulrich, 1981; Ulrich et al., 1991; Wise & Rosenberg, 1988). Clinical studies have demonstrated effects on pain perception, on anxiety about procedures, and on call for “as needed” medications (Diette, Lechtzin, Haponik, Devrotes, & Rubin, 2003; Heerwagen, 1990; Miller, Hickman, & Lemasters, 1992, Nanda, Eisen, Zadeh, & Owen, 2010; Ulrich, Lunden, & Eltinge, 1993; Whall et al., 1997).
The human brain, theorists say, adapted to best appreciate natural configurations that appear to favor survival and well-being (Appleton, 1975; Orians, 1980; Orians, 1986; Orians & Heerwagen, 1992; Wilson, 1993; Wohlwill, 1983). Wohlwill suggested that the human brain and senses developed in natural environments and, therefore, have an easier time processing information from such environments, being relatively fatigued by information from the historically very recent alternative constructed environments.
Evolutionary theory about human relationship to landscape has expanded to include not only the idea that humans have been genetically steered to favor natural content over man-made structures and objects, but also to encompass the idea that humans are inclined to respond to certain types of landscape most positively. Many researchers have demonstrated this (Chang & Perng, 1998; Parsons, Tassinary, Ulrich, Hebl, & Grossman-Alexander, 1998; Ulrich, 1979; Ulrich, 1981; Ulrich et al., 1991): Savannah-like (park-like) settings, especially with fresh, calm waters included, are favored over other types of scenes cross-culturally (Ulrich, 1993), as seen with American, British, Canadian, Chinese, Swedish, and Ugandan (Ulrich, 1983), as well as Australian (Hertzog, Herbert, Kaplan, & Crooks, 2000) research participants. An ongoing series of survey studies spanning several years was begun to investigate “most liked” and “least liked” features of pictures in as many countries across the globe as would participate (Wypijewski, 1997). To date, this research has demonstrated that a park-like setting with blues, greens, and fresh water is the most favorite type of scene, while linear abstract is the least favorite. This has held true universally to date, including Asian, Middle Eastern, East African, European (eastern and western), and North American samplings.
Ulrich (1993) proposed that security and “restoration” (recovery from stress response; p. 88) are the subjective qualities identified with evolutionary advantage (survival and health) that underlie the objective elements in the preferred settings—low growth mixed with trees, flat areas through which to move, horizon, and water to drink. Flowers may also be part of a preferred setting because of their evolutionary association with food resources (Heerwagen & Orians, 1993; Kim & Mattson, 2002).
Kaplan (1978) contributed to the development of thought on the basis for human response to natural landscapes by providing a more specific idea about the cognitive mechanism through which viewing natural settings might work to reduce stress and provide a restorative experience. He distinguished “voluntary attention,” or attention requiring effort, from “involuntary attention,” or attention requiring no effort (p. 85). According to Kaplan, voluntary attention (to time schedules, to behavior, to conversation, to health care regimens, to environmental and social cues, to tasks, etc.) requires internal suppression of distraction and creates mental fatigue. Resting this overworked cognitive state may be achieved by having attention be taken up involuntarily—by environments or environmental images that are innately interesting and that fascinate without conscious effort. Kaplan also incorporated evolutionary predisposition into his explanation at this point. From evolutionary theory, he concluded that certain images evoke involuntary attention as a survival mechanism. These images include “green things . . . gardens . . . patterns of natural vegetation . . . water” (p. 88) and are “innately fascinating, . . . attention [to them] requir[ing] no effort,” (p. 86) as “survival may well have depended upon paying immediate attention to stimuli of this kind” (p. 86). This sort of attention would be instinctual and immediate, not consciously directed (Ulrich, 1983). Kaplan's premise is that attending to natural settings, or images of them, dispenses with conscious effort, and thereby reduces stress, and leads to survival advantages associated with psychological rest. From such reflections on cognitive states, stress, and restorative requirements came the idea that viewing select natural settings (innately associated with stress-reducing factors of safety, rest, and satisfaction of hunger and thirst) may counteract the stress reaction and provide some health benefit to people in stressful situations (Ulrich & Parsons, 1992).
What has thus far been overlooked in the interventions and products based on these theories and studies rooted solely in “biophilia” (Wilson, 1993—the idea that humans have an innate attraction to living things, a predisposition to focus on and respond to scenes of natural content) is the importance of pattern to human recognition of these restorative scenes. A study at NASA began to elucidate this factor. The human brain seems to be partial to certain patterns of natural landscape more than others.
We do know that many natural scenes are fractal—having patterns of shape that recur on finer and finer scales throughout the visual frame (Taylor et al., 2005). A fractal dimension may be calculated for photographic images and will range between 1.0 (a line) to 2.0 (a plane) on a logarithmic scale (Wise & Taylor, 2002). This range represents a progression in complexity, for example, an image of fluffy clouds might have a fractal dimension of 1.3, while a briar patch might have a fractal dimension of 1.8 (Wise & Taylor). Wise and Taylor hypothesized that the calming effect of natural landscape images might have to do with brain neurocircuitry evolutionarily programmed to recognize a fractal range in these scenes that corresponds to the fractal range of environments in which humans developed as a species.
Wise and Rosenberg (1988) noted, “Although certain types of trees, foliage and landforms may be highly preferred or particularly evocative, this does not imply that the active agent is in the thing itself rather than in what the thing displays” (p. 11). This idea was demonstrated by VonTonder, Lyons, and Ejima (2002). These investigators mathematically analyzed a Japanese meditation garden renowned for its meditative and relaxing character and found that, although the objects in the visual field they examined are rocks, what is seen may actually be pattern, not individual features. These rocks make the shape of a tree with extended limbs when geometric functions are applied to their positioning. VonTonder, Lyons, and Ejima suggested the brain may interpret and respond to “tree” rather than “rocks” when viewing such a scene.
In a head-to-head comparison of the stress-reducing effect of two different natural landscape scenes (Wise & Rosenberg, 1988), the one having a fractal dimension comparable to the range in the African savannah (1.3-1.5; Wise & Taylor) was the more effective at reducing a physiological manifestation of stress response (skin conductance). Kaplan mentioned the significance of pattern and stated, “An individual's likelihood of survival would be enhanced if certain kinds of patterns . . . were innately fascinating, if attention [to them] required no effort” (p. 86). With their finding about pattern, quantified as fractal dimension, Wise and Taylor demonstrated mathematically what the earlier theorists and researchers had proposed intuitively.
Reaction to pattern (fractal dimension) as part of an evolutionarily adaptive approach-avoidance response would occur at the lower levels of brain function, the limbic system (Wise & Rosenberg, 1988; Ulrich, 1983) and would, therefore, be expected to occur quickly (without conscious thought) and would not be limited by ethnicity, age, gender, or geographic location, as seems to be the case across various studies (cited above). These findings support the idea of the new intervention—evidence-based landscape images (i.e. having specific content as specified above) further qualified by mid-range fractal character—that can affect manifestations of stress in the general human population.
The study titled, “Use of Natural Landscape Photographs with Particular Content and Pattern to Reduce Agitation in Nursing Home Residents with Alzheimer's Dementia” by P. Martin, Applicant (University of Rochester, Rochester N.Y.; see U.S. Provisional Application 61/534,546), which is also hereby incorporated by reference in its entirety, tested this new intervention idea as a nonpharmacological approach to reduce agitation in elders, thought to be brought on by stress reaction. Although aspects of the disclosed embodiments may be described relative to reducing agitation in a nursing home setting, it will be appreciated that the disclosed methods and systems are equally applicable to humans in the general population. The use of natural landscape scenes does not necessitate individualized equipment, space for interaction, supervision, training, or learning and recall by the user. In fact, such use may not even require an awareness or voluntary attention. The use of natural landscape scenes with particular content and pattern is, therefore, easy and accessible, making it a potentially valuable non-pharmacologic tool for addressing stress and its many negative sequelae.
As a general rule, not just any picture of a landscape or seascape will have a desired or optimized effect of evoking a relaxation response. Rather, as has been described herein, a specific combination of image content and average fractal dimension are used to determine or identify images that are qualified to evoke desired responses, meaning they will elicit a relaxation response in the general population. These characteristics are essential for a picture or image to evoke a positive psychophysiological response. The recognition and quantification of recurring patterns within an image (including a characteristic represented by an average fractal dimension for an image) as an ingredient for imagery to be maximally calming and satisfying has yet to be applied in conjunction with images of specific natural landscape features for the purpose of qualifying images that create a visual relaxation tool as illustrated and described in the embodiments herein.
Disclosed in embodiments herein is a method for eliciting a relaxation response, the method comprising: obtaining, using a computing device, a plurality of images; selecting a subset of images, from said plurality of images, satisfying a plurality of natural landscape selection criteria; calculating, with the computing device, an average fractal dimension for each of the images in the subset over a range of thresholds; retaining, within memory accessible by a relaxation response display device, each of the images from the subset having a calculated average fractal dimension within a pre-determined range; and providing the retained images in a serially arranged sequence, and displaying said sequence of images on a relaxation response display device.
Also disclosed in embodiments herein is an apparatus including at least one processor configured to execute programmed instructions stored in memory for calculating an average fractal dimension of an image qualified to elicit a relaxation response from a viewer, comprising: a) thresholding the image (i.e. transforming the image into black and white by applying a threshold against which an actual image intensity value is compared and thereby assigning chosen intensity bounds to be black/white) at a threshold (T) to create a thresholded image; b) covering at least a portion of the thresholded image with boxes; c) counting a number of boxes needed to cover the black/white interface in the thresholded image; d) plotting, a graph for the image with a horizontal (x) axis for the graph being a logarithmic representation of the box size and a vertical (y) axis for the graph being a logarithmic representation of the number of boxes needed to cover the black/white interface in the thresholded image; e) determining a slope of a graphed function relating box size and box count for the thresholded image, which is the fractal dimension for the image at the threshold (T); f) storing the fractal dimension for the thresholded image; g) repeating (a)-(f) for a plurality of thresholds over a range of thresholds; and h) calculating an average of the calculated fractal dimensions for the image based upon the plurality of thresholded images created within the range of thresholds.
Further disclosed in embodiments herein is a relaxation response apparatus, comprising: at least one processor; a memory, coupled to the at least one processor which is configured to execute programmed instructions stored in the memory including: obtaining a plurality of images; selecting a subset of images from the plurality of images which satisfy a plurality of natural landscape selection criteria; calculating a fractal dimension for each of the images in the subset of images; retaining for display only those images from the subset having a calculated average fractal dimension within a predetermined range; storing the retained images in memory in a sequence; and a display for displaying the retained images in the sequence.
The various embodiments described herein are not intended to limit the disclosure to those embodiments described. On the contrary, the intent is to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the disclosure.